PHP Unconference Europe 2015

get_parent_class

(PHP 4, PHP 5)

get_parent_classRecupera el nombre de la clase padre de un objeto o clase

Descripción

string get_parent_class ([ mixed $object ] )

Recupera el nombre de la clase padre de un objeto o clase.

Parámetros

object

El objeto evaluádo o nombre de la clase. Este parámetro es opcional si se invoca desde el método del objeto.

Valores devueltos

Devuelve el nombre de la clase padre de la clase de la cuál object es una instancia o el nombre.

Nota:

Si el objeto no tiene padre o la clase dada no existe devolverá FALSE.

Si se llama sin parámetro fuera del objeto, esta función devolverá FALSE.

Historial de cambios

Versión Descripción
5.1.0 Si se llamaba sin parámetro fuera del objeto, está función devolvía NULL con una advertencia, pero ahora devuelve FALSE.

Ejemplos

Ejemplo #1 Usar get_parent_class()

<?php

class papá {
    function 
papá()
    {
    
// implementar algo lógico
    
}
}

class 
hijo extends papá {
    function 
hijo()
    {
        echo 
"Soy hijo de " get_parent_class($this) , "\n";
    }
}

class 
hijo2 extends papá {
    function 
hijo2()
    {
        echo 
"Yo también soy hijo de " get_parent_class('hijo2') , "\n";
    }
}

$foo = new hijo();
$bar = new hijo2();

?>

El resultado del ejemplo sería:

I'm dad's son
I'm dad's son too

Ver también

  • get_class() - Devuelve el nombre de la clase de un objeto
  • is_subclass_of() - Verifica si el objeto tiene esta clase como uno de sus padres

add a note add a note

User Contributed Notes 10 notes

up
1
levu
3 years ago
I wrote a simple function doing the reverse thing: get the children:

<?php
function get_child($instance, $classname) {
   
$class = $classname;
   
$t = get_class($instance);
    while ((
$p = get_parent_class($t)) !== false) {
        if (
$p == $class) {
            return
$t;
        }
       
$t = $p;
    }
    return
false;
}

abstract class
A {
    function
someFunction() {
        return
get_child($this, __CLASS__);
    }
}

class
B extends A {

}

class
C extends B {

}

$c = new C();
echo
$c->someFunction(); //displays B

?>
up
0
falundir at gmail dot com
2 years ago
You can use this function to find common parent of multiple objects or classes.

<?php
/**
* Returns name of the first (in class hierarchy) common parent class of all provided objects or classes.
* Returns FALSE when common class is not found.
*
* @param mixed $objects Array that can contain objects or class names.
* @return mixed
*/
function get_first_common_parent($objects) {
   
$common_ancestors = null;
    foreach(
$objects as $object) {
        if (
is_object($object)) {
           
$class_name = get_class($object);
        } else {
           
$class_name = $object;
        }
       
       
$parent_class_names = array();
       
$parent_class_name = $class_name;
        do {
           
$parent_class_names[] = $parent_class_name;
        } while(
$parent_class_name = get_parent_class($parent_class_name));
       
        if (
$common_ancestors === null) {
           
$common_ancestors = $parent_class_names;
        } else {
           
$common_ancestors = array_intersect($common_ancestors, $parent_class_names);
        }
    }
   
    return
reset($common_ancestors);
}
?>

Example:

<?php
class A {
}

    class
B extends A {
    }
   
        class
D extends B {
        }
       
        class
E extends B {
        }

    class
C extends A {
    }

        class
F extends C {
        }
   
            class
G extends F {
            }

class
H {
}

//returns "A"
get_first_common_parent(array('G', 'E'));

//returns "F"
get_first_common_parent(array(new G(), 'F'));

//returns false (no common parent)
get_first_common_parent(array('C', 'H'));

//returns false (non-existent class provided)
get_first_common_parent(array(new B(), 'X'));
?>
up
0
michael at getsprink dot -- com
5 years ago
This little snippet to get the inheritance tree might be useful to someone.

<?php

header
("Content-Type: text/plain;");

class
Top {
  public function
getParents($class=null, $plist=array()) {
   
$class = $class ? $class : $this;
   
$parent = get_parent_class($class);
    if(
$parent) {
     
$plist[] = $parent;
     
/*Do not use $this. Use 'self' here instead, or you
       * will get an infinite loop. */
     
$plist = self::getParents($parent, $plist);
    }
    return
$plist;
  }
}

class
Middle extends Top {
 
}

class
Bottom extends Middle {
 
}

$o = new Bottom();
print_r($o->getParents());

?>
up
0
ssb45 at cornell dot edu
6 years ago
"'If called without parameter outside object' What on earth does that mean?"

There are two places this could be called:
1. From within a member function of an object.  In this case, it may be called with no parameters and will return the parent class of the object owning the member function.  (If the parameter is included, then it will return the parent class of the specified class as normal.)

2. From outside an object (i.e., global or function scope).  In this case, PHP doesn't know what class you're talking about if you don't include a parameter, so it returns FALSE.  (But, of course, it works if you specify the class with the parameter.)
up
0
marcus at synchromedia dot co dot uk
6 years ago
"If called without parameter outside object" What on earth does that mean?

What I can tell you, and that is not documented, is that if the object in question does not have an explicitly declared parent class, it does return boolean false. It doesn't for example return 'stdClass' on the basis that all objects are derived from that.
up
0
birkholz at web dot de
9 years ago
tim at correctclick dot com wrote:
<quote>
A slightly more cryptic but faster get_ancestors function:

<?php
function get_ancestors ($class) {
         
     for (
$classes[] = $class; $class = get_parent_class ($class); $classes[] = $class);
     return
$classes;
     
}
?>
(The second part of the for is implicitly testing for $class != "").  Recursion is considerably slower than looping, so you probably want to use this function.

Hope someone finds it useful.
</quote>

I would prefer this version, because it will create no duplicates:
<?php
function get_ancestors ($class) {
   
$classes = array($class);
    while(
$class = get_parent_class($class)) { $classes[] = $class; }
    return
$classes;
}

Greets, Dennis
?>
up
0
matt-php at DONT-SPAM-ME dot bitdifferent dot com
9 years ago
PHP (4 at least, dunno about 5) stores classnames in lower case, so:

<?PHP

class Foo
{
}

class
Bar extends Foo
{
}

echo
get_parent_class('Bar');

echo
"\n";

echo
get_parent_class('bar');

?>

will output:

foo
foo
up
0
radu dot rendec at ines dot ro
10 years ago
If the argument obj is a string and the class is not defined, then the function returns FALSE.

If the argument obj is an object created from a class with no ancestors (or a string representing a class with no ancestors), then the function returns FALSE.
up
0
tim at correctclick dot com
11 years ago
A slightly more cryptic but faster get_ancestors function:

function get_ancestors ($class) {
           
      for ($classes[] = $class; $class = get_parent_class ($class); $classes[] = $class);
      return $classes;
       
}

(The second part of the for is implicitly testing for $class != "").  Recursion is considerably slower than looping, so you probably want to use this function.

Hope someone finds it useful.
up
-1
eric dot brison at anakeen dot com
12 years ago
To return all ancestors class of an object

function get_ancestors_class($classname) {
  $father = get_parent_class($classname);

  if ($father != "") {

    $ancestors = get_ancestors_class($father);
    $ancestors[] = $father;
  }
  return $ancestors;
}

example :
-----------
Class C  {

}

Class B extends C {

}

Class A extends B {

}
print_r (get_ancestors_class("a"));
print_r (get_ancestors_class("b"));

example result :
---------------
Array
(
    [0] => c
    [1] => b
)
Array
(
    [0] => c
)
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